Health officials say a boil water advisory for six northwest Calgary neighborhoods will likely remain in effect throughout the weekend and taps are running dry at a number of area schools because of the cloudy water.  Deborah Fairhurst is the principal at Hidden Valley School and says special measures are in place to protect students, including bringing in bottled water.  Hand sanitizers have been placed in the washrooms for students to use while the advisory is in effect.  Fairhurst says Calgary Board of Education officials also helped by bringing in 16 cases of bottled water before the morning bell rang on Friday.  She says it was also an interesting situation, as students at a neighboring junior high school are involved in charity project that's helping build a water well for students in Ecuador.  The school was also hosting a parent volunteer appreciation event on Friday, which was both a help and a hinderance, with the need for water but at the same time, allowed them to get the word out.